When should you treat a sports injury yourself, and when should you stop playing until you see a physician? Here are a few sports injuries that you should know about.

Head injuries/concussions

Don't take chances with a concussion or any other head injury.

The brain is composed of tissue with the consistency of gelatin and is normally cushioned by spinal fluid. A concussion occurs when the brain knocks against the bony surface of the skull. Injuries that can occur to the brain in a concussion are bruising, tearing blood vessels, stretching nerve fibers and increase in the pressure inside the skull as a result of bleeding or swelling. In a concussion, normal brain function is affected.

Concussions can be caused by a blow to the head or by a rapid deceleration that causes the brain to slosh inside the skull. According to the Centers for Disease Control and Prevention (CDC), 1.6 million to 3.8 million concussions due to sports- and recreation-related activities occur each year.

The American Association of Neurological Surgeons (AANS) says that about 300,000 concussions occur each year in high school, college, and professional football players and that the risk of concussion in football is three to six times higher in players who have had a previous concussion.

In most cases, concussions do not cause a loss of consciousness. One concussion does not usually cause permanent damage, but the AANS warns that there is no such thing as a "mild concussion."

A health care provider should always be consulted, especially if any of these symptoms occur:

Have one pupil -- the black part in the middle of the eye -- larger than the other

Convulsions or seizures

Slurred speech

Getting more and more confused, restless or agitated

Symptoms in children that require immediate medical attention:

Any of the danger signs for adults (see above)

Child won't stop crying

Child can't be consoled

Child won't nurse or eat

Post-concussion syndrome can occur to people who suffer a head injury. They may have poor memory and concentration, headache, fatigue and dizziness for weeks or months after the injury. In children who have even a moderate concussion, there may be an increase in irritability, angry behavior and meanness for up to a year. The AANS recommends that athletes not return to play while they have these symptoms and that those who have had repeated concussions should consider ending participation in that sport.

Neck injuries

The neck supports the head and is very flexible, so many injuries to the neck occur from a fall or an abrupt jerking of the head (whiplash). Neck pain can be caused by strains, sprains or fractures. Strains and sprains are injuries to the muscles and ligaments. Pain can also come from injury to nerves that branch from the neck into the arms and hands. The action that injures a neck does not have to be sudden. Injury can occur over a period of time from activities that strain the neck such as mountain bike riding and horseback riding.

Symptoms that indicate medical attention is necessary:

Neck pain after an injury; if the pain is severe, the person should not be moved and emergency medical personnel should be called

Pain or numbness radiating down an arm, or weakness in an arm

Pain that continues for a period of time

If severe neck pain occurs after an injury, such as in a motor vehicle accident, diving accident or fall, a trained professional, such as a paramedic, should immobilize the person to avoid the risk of further injury and possible paralysis. Seek immediate medical care.

Immediate medical care should also be sought when an injury causes pain in the neck that radiates down the arms and legs. Radiating pain or numbness in your arms or legs that causes weakness in the arms or legs without significant neck pain should also be evaluated.

The treatment for neck pain depends on the cause. Most often a combination of rest, medication and immobilization are successful. If these are not effective, physical therapy and occasionally surgery are needed.

Elbow tendonitis

The elbow is formed by three bones: the bone of the upper arm (humerus) and the two bones of the forearm (radius and ulna). The two bony knobs at the end of the humerus are called epicondyles. Tendons attach muscles to bones at the epicondyles. These muscles move the wrist and fingers. Overuse of these muscles in sports or other activities can cause the tendons to become inflamed or torn. This condition is commonly known as "golfer's elbow" or "tennis elbow."

A symptom of elbow tendonitis is pain while doing activities that involve the wrist and fingers, such as using a screwdriver, hammer or scissors. Pain may continue even when the hand is resting.

Treatment usually is rest from the activities that cause pain and ice to the sore area several times a day for 20 minutes.

See a doctor if the pain persists. Your doctor may suggest strengthening exercises and ways to modify your activities, such as straps that relieve stress on the tendons or braces. Over-the-counter or prescribed medications can reduce the inflammation and relieve pain. Other treatments are cortisone shots and surgery.

Shoulder injuries

The shoulder is made up of three joints. The glenohumeral joint is a ball and socket joint linking the collarbone (clavicle) to the upper arm bone (humerus). The acromioclavicular joint joins the shoulder blade (scapula) to the clavicle. The third joint, scapulothoracic, joins the scapula to the back of the rib cage. The rotator cuff, four muscles that surround the shoulder, stabilize it. Tendons attach these muscles to bones. Bursa, or small fluid-filled sacs, decrease friction during shoulder movements.

The shoulder is the most flexible joint in the body. Because of this flexibility, it is vulnerable to injury. Most injuries to the shoulder are to the muscles and ligaments; seldom are bones injured. Shoulder injuries are common in sports that require overhead motion like swimming, tennis, pitching and weightlifting.

The American Academy of Orthopedic Surgeons (AAOS) suggests that you see a health care provider if you have any of the following symptoms after a shoulder injury:

Continuous pain

Stiff shoulder

Feeling as if your shoulder could pop out or slide out of the socket

Decrease in shoulder strength or movement so that you cannot carry on with daily activities

Treatment for most shoulder injuries is rest and ice several times a day for 20 minutes and over-the-counter or prescribed anti-inflammatory medications. If these don't work, your health care provider might suggest strengthening exercises.

See a doctor immediately if you cannot lift your arm or if the shoulder is very painful, swollen and discolored. Your shoulder may be dislocated.

Knee injuries

The knee joins the lower end of the thighbone (femur), the shinbone (tibia) and the kneecap (patella). It is the largest joint in the body and bears much of the body's weight. Large ligaments connect the bones and stabilize the joint. Cartilage (meniscus) forms a cushion between the bones and absorbs shock during motion.

Common athletic injuries to knees involve blows to the knee, and twisting, jumping, slowing down when running and changing directions. Most often, it is the ligaments of the knee that are injured. Sports in which knee injuries are common are basketball, skiing and those that require athletic shoes with cleats.

Symptoms that require medical attention after a knee injury:

Pain accompanied by swelling or redness

Deformed joint

Pain over the kneecap

Inability to stand (knee "buckles")

Difficulty walking or inability to walk

Knee "locks" and won't bend

Hearing a "pop" when the knee was injured

For minor pain, try RICE: Rest, Ice, Compression and Elevation. Your health care provider might suggest over-the-counter or a prescribed anti-inflammatory medication. If this does not work, see your provider. Further treatment will depend on the cause of knee pain.